To exclude any potential confounding factors due to immunodeficiency in the NSG model, we next evaluated the effects of L72-FSY using an IL-2Rα-humanized B6 mouse model (B-hIL2RA mice), in which the ectodomain of IL-2Rα was completely replaced with humanized IL-2Rα. Here, IL2RA is linked to immunodeficiency disease.